1. Field
The inventive concept relates to methods of forming patterns and to methods of manufacturing integrated circuit (IC) devices having patterns. The inventive concept also relates to a double patterning technique of forming patterns of a semiconductor device.
2. Description of the Related Art
The manufacturing of integrated circuits (ICs) entails the forming of various types of fine patterns, e.g., a series of openings or trenches in a layer, a series of conductive lines, etc. These patterns have what is referred to as critical dimensions (CD). A critical dimension (CD) is a dimension specified in the design process, such as the diameter of an opening, width of a line-shaped feature or pitch, i.e., an interval between adjacent ones of the features.
Pattern miniaturization is essential for manufacturing highly integrated semiconductor devices. To integrate a large number of devices within a narrow area, the sizes of the individual devices have to be as small as possible, and the pitch of the features and the width of a single feature also have to be small. However, with the rapidly reduced design rule of semiconductor devices and the limited resolution in photolithography processes, there is a limit to the critical dimension that can be attained in a pattern of a plurality of holes formed in a layer of the device. There have been various techniques developed aimed at forming a pattern of a plurality of holes with a small CD using a conventional photolithography processes but the resolution of conventional photolithography imposes a limit on scaling down a pattern of a plurality of holes. Thus, it remains difficult to manufacture highly integrated IC devices.